1. Field of the Invention
The present invention relates to a structure of a parabolic antenna, and more particularly, a structure of a parabolic antenna having radiating elements placed in front of a parabolic dish.
2. Description of the Prior Art
Wireless radio links are used to transmit data from one location to another. Wireless transmissions are frequently bidirectional. The wireless radio links utilize electromagnetic radiation of a specified frequency and data-encoding scheme. An antenna is used to transmit the electromagnetic radiation from one location to another location where it is received by another antenna and decoded for use at the second location. Typically, there is a line of sight path between the radio link antennas, so the path of the radio wave propagation is free from obstructions.
An antenna may not radiate in the same way in all directions. One class of antenna is designed to radiate strongly in one direction only. Radio link antennas are used to transmit data over large distances. Thus, it would be advantageous to be highly directional so that it causes fewer disturbances to other antennas.
Conventionally, antennas use waveguides to guide the electromagnetic radiation. There are different types of waveguides for each type of wave. The original and most common meaning for a waveguide is a hollow conductive metal pipe used to carry high frequency radio waves, particularly microwaves. Though waveguides may be used to guide the electromagnetic radiation to a desired direction, the production of waveguides is costly. Hence, there is a need to develop an antenna that would be able to uniformly propagate to desired direction without the use of waveguides.